Just after 4 p.m. on September 6, 1901, twenty-eight year old anarchist Leon Czolgosz pumped two shots into the chest and abdomen of President William McKinley. Czolgosz had been on a receiving line waiting to shake the president<U+2019>s hand, his revolver concealed in an oversized bandage covering his right hand and wrist. McKinley had two Secret Service agents by his side, but neither made a move to stop the assailant. After he was apprehended, Czolgosz said simply, “I done my duty.” Both law enforcement and the press insisted that Czolgosz was merely the tip of a vast and murderous conspiracy, likely instigated by the “high priestess of anarchy,” Emma Goldman. To untangle its threads and bring the remaining conspirators to justice, the president<U+2019>s most senior advisors choose two other Secret Service agents, Walter George and Harry Swayne. What they uncover will not only absolve the anarchists, but also expose a plot that will threaten the foundations of American democracy, and likely cost them their lives.